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Biomedical subjects

M Samama

Publications and source records attributed to M Samama.

At least 37 records · Page 2Linked to original sources
PubMed1977

[Volume distribution studies on the platelet populations (author's transl)].

The volume distribution into human platelet populations was investigated in order to determine if thereis a relationship between the cell density and the cell size and if the isolated platelets are homogeneous populations of cells. The platelet populations were isolated from platelet rich plasma or from washed platelets by isopycnic centrifugation on sucrose density gradients. Platelet volume was measured electronically with Coulter F or Coulter Z Bic coupled with Channelyser C 1000. The results show that there exists a direct relationship between platelet density and size, since the volumetric parameters gradually increase from the small platelets of lower density to the larger ones isolated at higher density. Evidence was also obtained that the isolated populations of platelets were heterogeneous and their volume distribution was log-normal. Both the heavy and the light platelet populations were found as a mixture of mainly large or mainly small platelets respectively.

Blood Platelets↗
PubMed1977

[Study of the bleeding mechanism during fibrinolysis induced by streptokinase in the rabbit (author's transl)].

Our aim in this work has been to obtain precisions on the bleeding mechanism during fibrinolysis induced by streptokinase in the rabbit. Haemostasis was studied in vivo by the method oh Honour and Russell. The injection of 40 000 u/kg of streptokinase in 10 minutes induces rapidly fibrinolysis, which lasts for approximately one hour which is not accompanied by changes either in coagulation factors, or in platelet function. In vivo : . the adhesion of platelets to the vascular lesion is normal; . platelet aggregation is normal as is the formation of intravascular thrombi; . on the other hand the intra mural platelet thrombus is unstable. The embolization of the intravascular thrombi is responsible for new hemorrhages which can be correlated with the intensity of fibrinolysis. Thus, even in the absence of fibrinogenolysis, of fibrinogen degradation products FPD, of abnormal thrombin generation and of altered platelet function, the fibrinolytic activity induced by streptokinase could alone be responsible for bleeding episodes, occuring during thrombolytic treatment by streptokinase in man.

Animals↗
PubMed1976

[Quantitative determination of Willebrand factor activity in Willebrand's disease].

Certain new data about the nature of Willebrand factors are discussed, its activity being considered as part of the activity of the antihemolytic factor VIII. An one-stage method for its determination is described based on the absence of thrombocytic aggregation in the presence of ristocetin in the patients with Willebrand disease as well as the illustration of one case.

Adult↗
PubMed1976

Human platelet fibrinogen: a protein different from plasma fibrinogen.

Fibrinogen has been purified from normal and dysfibrinogenemia Metz plasmas, and from normal and from the patient's platelets. There are differences in the pattern of disc polyacrylamide gel electrophoresis between normal plasma and normal platelet fibrinogens, but the migration of the A alpha chain is similar. The abnormality of the electrophoretic mobility of the A alpha chain of plasma fibrinogen from Metz dysfibrinogenemia is not found in platelet fibrinogen of this patient. This result clearly establishes that platelet fibrinogen is a different protein from plasma fibrinogen.

Adult↗